• Horticultural Science & Technology
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• v.31 no.3
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• pp.328-336
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• 2013

This study was conducted to evaluate imported tomato $F_1$ cultivars as breeding materials for the resistance to Tomato yellow leaf curl virus (TYLCV) by molecular markers and bioassay. From marker genotyping and disease evaluation of 40 $F_1$ cultivars, most of the cultivars declared as TYLCV-resistance carried heterozygous marker genotype for the TYLCV resistance genes Ty-1, Ty-3, or Ty-3a, and showed low disease rates. Whereas, 4 of 5 $F_1$ cultivars declared as intermediate resistance showed marker genotype for susceptibility and disease rates ranged 18.1-33.3%. However, the xx cultivars showed inconsistency in marker genotype and disease rate. Characterization of horticultural traits of the $F_1$ cultivars with TYLCV-resistance indicated that large-size fruit cultivars were higher in yield and similar in sugar contents and solid-acid ratio compared to a control cultivar preferred in the domestic market, although hardness remained to be a problem. On the other hand, cherry tomato cultivars showed lower yield and brix, but longer internode compared to a control cultivar, indicating that breeding for TYLCV-resistance using these cultivars will require more efforts and time compared to large-sized.

• Journal of Bio-Environment Control
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• v.21 no.1
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• pp.12-19
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• 2012

This research was performed to determine the appropriate daily last irrigation time to enhance the plant growth and the water and fertilizer use efficiencies in coir bag culture for tomato plant. The time to finish the daily irrigation was set by 1, 2, 3 and 4 hours before the sunset. The water content in the substrate was greatly affected by the last irrigation time. The earlier the last time, the greater the daily fluctuation of water contents in the substrate. The daily irrigation times were not affected by using irrigation management system controlled by drainage electrodes or the physiochemical properties of coir. The growth characteristics were not significantly different among the treatments. The highest marketable yields were obtained in the treatment finishing two hours before sunset, and the lowest yields were obtained in the the treatment finishing 4 hours before sunset. Based on the result from surveying quantity of irrigated water for 128 days of the experiment period, the water and fertilizer use efficiencies were lowest in the treatment finishing 4 hours before sunset, and the highest in the treatment finishing 2 hours before sunset. In terms of plant growth, yields, water and fertilizer use efficiencies, 2 hours before sunset treatment was determined as the most economical and desirable irrigation schedule.

• Research in Plant Disease
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• v.23 no.3
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• pp.228-233
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• 2017

Six commercial rootstock varieties were tested for resistance to bacterial wilt (Ralstonia solanacearum) by dipping the roots of seedlings in the bacterial suspension at seedling stage. 'Shincheonggang' and 'B-Blocking' ranked top and second in resistance to bacterial wilt, respectively. For disease index of the grafted plants, 'Dotaerang' grafted onto 'Shincheonggang' was the least, followed by 'Ultra', 'Fighting', 'B-Blocking', 'Special', and 'Connection' grafts. Thus, disease development on the grafted plants was correlated with resistance of rootstocks. The effect of rootstocks on horticultural characteristics including days to flower of scion was minimum or negligible. In correlation between horticultural characteristics of rootstocks and scions grafted thereon, statistically significant negative correlation was observed in days to flower and fruit height but no significant correlation was observed in yield per plant, fruit diameter and soluble solid content in the fruits. Thus, selection of resistant rootstock varieties that support the growth and yield of scion well is necessary for effective control of the disease and yield increase.

• Research in Plant Disease
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• v.20 no.4
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• pp.253-258
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• 2014

This study was conducted to evaluate tomato plant resistance against bacterial wilt by Ralstonia solanacearum using tomato cultivars or tomato breeding lines maintained in RDA-Genebank of Rural Development Administration and to select resistant tomato lines for breeding purpose. We evaluated the disease responses of a total of 13 cultivars and 39 breeding lines from RDA-Genebank using R. solanacearum SL341 strain, which is a representative strain in Korea. Tomato cultivar Hawaii 7996 and Moneymaker were used as a resistant control plant and a susceptible control plant, respectively. A total of 32 cultivars were susceptible and 10 cultivars showed various disease response suggesting resistant phenotype segregation in the lines. Five commercial cultivars and 5 breeding lines exhibited strong resistance to bacterial wilt by the SL341 strain. These 5 breeding lines might be used for further study of plant defense response against bacterial wilt and cloning of the resistance gene from tomato plants. Ultimately, the selected lines could be used for tomato breeding to generate bacterial wilt resistant tomato plants.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.627-637
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• 2010

The consumption of tomato has greatly increased recently in Korea, and a large number of tomato cultivars are commercially available in the market. However, identification of tomato cultivars by morphological traits is extremely difficult because of the narrow genetic diversity of breeding lines. Therefore, it is necessary to develop molecular markers for cultivar identification in tomato. In this study, we surveyed single nucleotide polymorphism (SNP), and developed SNP marker sets for tomato cultivar identification. SNP markers were developed based on conserved ortholog set II (COSII) and intron-based markers derived from pepper EST sequences, and marker polymorphism was tested using high-resolution melting (HRM) analysis. A total of 628 primer sets was tested, and 417 primer sets amplifying single bands were selected. Of the 417 primer sets, 70 primer sets showing HRM polymorphism among 4 inbred lines were selected. Eleven markers were selected from the 70 primer sets and subjected to cultivar identification analysis. Thirty two commercial tomato cultivars were successfully identified using the marker set.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.566-574
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• 2015

Yellow or transparent fruit peel color is caused by the accumulation or lack of naringenin chalcone (NG, C) in fruit peel and determines the red or pink appearance of tomato fruit, respectively. NGC biosynthesis is regulated by the SlMYB12 gene of the Y locus on chromosome 1, and DNA markers derived from SlMYB12 would be useful for marker-assisted selection (MAS) of tomato fruit color. To develop a gene-based marker, 4.9 kb of the SlMYB12 gene including a potential promoter region was sequenced from the red-fruited (YY) line 'FCR' and pink-fruited (yy) line 'FCP'. Sequence alignment of these SlMYB12 alleles revealed no sequence variations between 'FCR' and 'FCP'. To identify SlMYB12-linked single nucleotide polymorphisms (SNPs), 'FCR' and 'FCP' were genotyped using a SolCAP Tomato SNP array and CAPS markers (CAPS-456, 531, 13762, and 38123) were developed from the four SNPs (solcap_snp_sl_456, 531, 13762, and 38123) most closely flanking the SlMYB12. These CAPS markers were mapped using $F_2$ plants derived from 'FCR' ${\times}$ 'FCP'. The map positions of the fruit peel color locus (Y) were CAPS-13762 (0 cM) - 456 (11.09 cM) - Y (15.71 cM) - 38123 (17.82 cM) - 531 (30.86 cM), and the DNA sequence of SlMYB12 was physically anchored in the middle of CAPS-456 and CAPS-38123, indicating that fruit peel color in domesticated tomato is controlled by SlMYB12. A total of 64 SolCAP tomato germplasms were evaluated for their fruit peel color and SNPs located between solcap_snp_sl_456 and 38123. Seven SNPs that were detected in this interval were highly conserved for pink-fruited accessions and specific to transparent fruit peel traits, as depicted by a phenetic tree of 64 accessions based on the seven SNPs.

• Research in Plant Disease
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• v.15 no.3
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• pp.198-201
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• 2009

Bacterial wilts, caused by Ralstonia solanacearum, is a very destructive disease to tomato plants (Solanum lycopersicum) in Korea. Selection of resistant cultivar is the best way to prevent or reduce the occurrence of this disease. Thirty-nine tomato cultivars, twenty-one cherry tomato cultivars and thirteen rootstock tomato cultivars were inoculated with Ralstonia solanacearum, to evaluate tomato cultivars for resistance against bacterial wilts. Thirty-seven cultivars were highly susceptible to bacterial wilts and 61-100% of their whole tissue became wilted within 10 days after inoculation. Twenty-four cultivars showed moderate resistance and twelve were resistant to bacterial wilts. In an evaluation of 73 major commercial cultivars, 'Lilyance', 'TP-7', 'Choice', 'Dadaki', 'Akiko', 'Redstar', 'Match', 'B-blocking', 'Magnet', 'Support', 'Friend' and 'Special' were found to have a high level of resistance to bacterial wilts of tomatoes.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.771-780
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• 2014

In this study, we aimed to understand the effect of sorbitol and salicylic acid (SA) on quality and functional food contents of tomato. Sole or combined application of sorbitol and SA in different concentrations (0.5 mM and 1.0 mM) greatly improved the characteristics of tomato, such as red color tone, soluble solid content, hardness and weight as well as increasing the functional food contents such as of lycopene, anthocyanins and vitamins in comparison with the control. The cyanidin content increased approximately 52-61% and delphinidin contents also increased 20-24% and 39-41% in tomato plants treated with SA alone and sorbitol with SA, respectively. Furthermore, the sole or combined application of sorbitol and SA also increased the vitamin $B_1$ and C contents. In particular, vitamin C content was increased 1.2-fold by treatment with sorbitol alone and was increased 2-fold by SA treatment compared to the control. In the sorbitol with SA treatments, vitamin C content was approximately 4-fold increased relative to control plants.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.783-789
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• 2010

The effective method for heating root-zone during winter season was studied in the aspects of growth, yield and economics for tomato ($Solanum$ $lycopersicum$) in perlite bag culture. There were four root-zone heating treatments: two hours heating from one hour before to one hour after sunrise, four hours from two hours before to two hours after sunrise, 15 hours after sunset, and no heating. The growth characteristics of the upper parts of plants were not significantly different among the treatments, but root volume increased with longer heating of the root zone. The Plant Development Index, using stem diameter and the length between growing tip and the upper flowering truss, showed relation between yield per cluster and growth pattern. The treatment heating for four hours was the most economic in terms of growth and yield of tomato.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.409-414
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• 2010

The first drainage time in a day was controlled for precise irrigation management with low consumption of nutrient solution in tomato perlite bag culture system by measuring water level of drained water in drainage catchment part. This method automatically adjusted the irrigation time under any condition of light, temperature and humidity, resulting in stable water content in substrates. However, it was difficult to keep the time consistent as they were set. It drained with the deviation of 20 min in the treatment in which the first drainage time was set at 10:00 and 50 min in the treatment set at 10:30. The first drainage time was not constant, but the drain occurred stably before noon in the treatment of which irrigation frequency was longer than 30 min. The drainage ratio was better balanced in all the treatments using drainage level sensors than the treatment using time clock for irrigation control. High water and fertilizer efficiencies were obtained. Although the growth, total yield and sugar content were not significantly different between the treatments, fruit weight was higher in the treatments using drainage level sensors than that using timer.